The Deputy Prime Minister criticised the Mayor for condoning “parking” a whole section of society for failing to be “up to scratch”.

Delivering the annual Margaret Thatcher lecture last night, Mr Johnson suggested tackling inequality was futile because people were “already very far from equal in raw ability”.

His remarks sparked immediate controversy with senior Labour politicians also lining up to criticise him for being out of touch.

In his Call Clegg show on LBC radio, Mr Clegg said: “I don’t agree with Boris Johnson on this. I think these comments reveal a fairly unpleasant, careless, elitism that somehow suggests we should give up on a whole swathe of our fellow citizens.

“Our job surely in politics is not to simply say look we’re going to hive off one bunch of people and put them in one kind of category and kind of basically say they’re parked, there’s not much we can do about them.”

While he praised the Mayor’s sense of humour, the Lib Dem leader was particularly critical of the “dispiriting” nature of his remarks.

“It seems to me that what we should be about in politics is encouraging people to get ahead in life, not basically saying to people well, no, if you’re not up to scratch you might as well give up,” he said.

Speaking to the right-wing Centre for Policy Studies think tank, Mr Johnson said: “I am afraid that violent economic centrifuge is operating on human beings who are already very far from equal in raw ability, if not spiritual worth.

“Whatever you may think of the value of IQ tests, it is surely relevant to a conversation about equality that as many as 16 per cent of our species have an IQ below 85, while about 2 per cent have an IQ above 130. The harder you shake the pack, the easier it will be for some cornflakes to get to the top.

“And for one reason or another – boardroom greed or, as I am assured, the natural and god-given talent of boardroom inhabitants - the income gap between the top cornflakes and the bottom cornflakes is getting wider than ever.

“I stress: I don’t believe that economic equality is possible; indeed, some measure of inequality is essential for the spirit of envy and keeping up with the Joneses that is, like greed, a valuable spur to economic activity.”

Labour’s mayoral hopefuls lined up to attack Mr Johnson’s remarks. Shadow minister for London Sadiq Khan said the Mayor was “shameless” for suggesting inequality was a good thing and people were poor because they were stupid.

“He has never had to struggle or fight to survive in his life. How could someone so out of touch with most Londoners lives possibly understand the reality of poverty in London?” he said.

“He is abandoning and exploiting poor Londoners to appeal to the far right of the Tory party and UKIP as he forgets London in his desperate scrabble to become Leader of his party.”

Tottenham MP David Lammy added: “Not only has Boris taken no interest in tackling the soaring inequality in our city - he is now actively promoting it. Under his leadership London is fast becoming a tale of two cities, with multi-billionaires living just down the road from families desperately struggling to pay the heating bills.

“And now he tells us that we should simply accept this as being “crucial” for economic growth. He has spectacularly missed the key point: economic growth in London should benefit all Londoners, not just the richest few.”